2000 3.0 ohv, car has about 130k on it. car runs a little cooler than usual so i change the thermestat, still the same problem. it gets heat at idle but as soon as i drive it goes cold. both hoses on the heater core feel hot, i tried searching and i think the heater core is fine, i mean both hoses are hot and the car actually runs a little colder than usual. this problem happened out of the blue, one day it was fine the next it did this. anyone expierence this?